can't add preference directly to root of prefs screen

I have a class that extends DialogPreference, and up until now, it's been living in a category under the main prefs screen. Now I want to bring it to the top level prefs screen. However, it's not showing up there.

When I call root.addPreference(buldDlg) isntead of syncCategory.addPreference(bulkDlg),
to get that setting to show up at the top level prefs screen, it doesn't work. The setting doesn't show up.

Some of the Android docs seemed a bit ambiguous, to me, even contradictory, but I THINK it should be possible
to do this. Am I wrong there? Or is there some special setup we have to do for the prefs screen or the Preference
itself in order to support this?